Some military guns are designed to fire ammunition of the "completely combustible" type. The term "completely combustible" is here used to mean an ammunition cartridge that is essentially all-propellant in character (i.e., caseless), or an ammunition cartridge wherein the propellant is housed within a combustible case.
U.S. Pat. No. 3,602,283 to Schlack and U.S. Pat. No. 4,213,392 to Usel show ammunition of the caseless cartridge type. U.S. Pat. No. 3,645,207 to Daniels and U.S. Pat. No. 3,901,153 to Brabets et al. show ammunition of the combustible case type.
In some instances, combustible cartridge ammunition experiences a "cook-off" problem. The term "cook-off" is here used to mean premature propellant ignition when the projectile-cartridge assembly is introduced into the gun. The problem is somewhat more troublesome with combustible ammunition because there is no brass cartridge case to absorb heat that otherwise radiates from the firing chamber wall into the cartridge propellant.
The present invention seeks to prevent cook-off problems associated with the firing of combustible cartridge ammunition.